Filter



April 16, 1940. C, A, BERGMANN 2,197,120

` FILTER Filed March 21,- 19:58 2 sheets-sheet 1 INVENTOR.

@Q1/0.51am

ATroRNEY.

April 16,. 1940- c. A. BERGMANN FILTER Filed March 21, 193B 2Sheets-Sheet 2 Patented Api. 1s, 1940 l UNITED STATEI PATENT orma FETEBCarl A. Bergmann, Milwaukee, Wis., assignor to Walter D. Mann,Milwaukee, Wis.

Application March 21,

6 Claims.

This invention relates to improvements in lters and more particularly toair or gas filters.

Present-day lters have only partial eiciency and are therefore notcapableo'f completely red -moving objectionable foreign matter fromairor gas. The present invention is designed to provide a filter of suchincreased emciency` that it may be successfully employed to removepollen or other ne particles from the air for the benefit l@ of hayfever suierers or othershaving an aln lergic reaction to certainmaterial in the air; to

remove smoke, vapors or oil mist from the air;

and to clean smoke and exhaust gases and remove dust from the air inindustrial plants.

It is a general object oi the present invention to provide an improvedfilter wherein centrifugal or inertia force is utilized to aid in theremoval of foreign matter from air or gas.

IA. more specific object of the invention is to 2o provide a lter havinga rotor, means rotatable with said rotor forming a plurality ofelongated passageways of relatively small radial width and preferablybut not necessarily extending transversely of the plane of rotation otthe rotor, and 2d means for propelling air to be cleaned through saidpassageways while the rotor is rotated, said air being subjected to theaction of centrifugal force whereby particles of foreign matter in theair are deposited by centrifugal force on the Walls of said passageways.

A further object of the invention is to provide a device as abovedescribed wherein the elongated passageways or filtering elements may beformed of corrugated board.

A further object of the invention is ,to provide a device of the classdescribed having an intake positioned exteriorly of an enclosure, meansfor drawing in air through said intake, means for conditioning said air,and means for admitting a regulated amountof air from within theenclosure to mix with said outside air.

A further object of the invention is to provide a lter as abovedescribed including'a rotor hav-1 ing anfopening positioned to releasemoisture or other foreign matter which is thrown centrifugally duringthe passage of the air through the rotor, certain forms of the inventionalso including means for adjustably varying the size of said releaseopening.

A further object of the invention is to provide a device as abovedescribed having means for imparting vibrations to the rotor as thelatter rotates to dislodge foreign matter in the elongated passagewaysand cause the same to travel toward release openings in the rotor.

1938, Serial No. 197,11

(Cl. 18S-47) A still further object of the invention is to provide alter, including means for drawing in air to the filter, and means foradjustably varyin the volume of air admitted.

With the above and other objects in view, the invention consists of theimproved lter and all its parts and combinations as set forth in theclaims and (all equivalents thereof.

In the accompanying drawings in which the same reference numeralsdesignate the same parts in all of the views:

Fig. l is a longitudinal vertical sectional view through one form or theimproved device;

Fig. 2 is a fragmentary sectional View taken on line 2--2 or Fig. 1;

lii'ig. 3 is a fragmentary sectional view of the rotor taken on line 3 3of Fig. l;

liig.v d is a fragmentary sectional view taken on line l-l of Fig. l;

Fig. 5 is an enlarged fragmentary cross sectional View of the filteringelement;

Fig.' 6 is a longitudinal vertical sectional view through another formof the device, particularly adapted for removal of smoke, vapor, oilmist, and other similar foreign matter from the air;

Fig. '7 is an enlarged fragmentary sectional view taken on line l-l oflilg. 6;

Fig. 8 is a vertical sectional view through an industrial type ofcentrifugal air cleaner particularlysuitable for the cleaning of smokeand exhaust gases and for thecollection of' dust;

liig. 9 is a cross sectional view of the rotor taken on line Q of Fig.8; and

Fig. lil is a fragmentary sectional view taken on line id-iti of Fig. 8and showing a slight modication.

Referring more particularly to Figs. l 4to 5 inelusive, the numeral iiindicates a frame structure having a base portion i2- and having anelevated platform portion i 3 for supporting an electric motor it. Themotor iii has a drive shaft l5 to which the inner drum it of a rotor ilis secured by a set screw or the like it. The peripheral wall portion cithe drum it projects inwardly to surround the motor it and is rotatablethere-around.

The rotor il comprises saidv inner drum it and an outer drum itl whichis spaced from the inner drum and which is preferably formed of twocomplementary sections bolted together as at 2t. Intake vanes 2l (seeFig. 2) join the inner drum l with the outer drum i9 as illustrated, andsaid vanes have curved inner end portions as shown in Fig. 2 toaccelerate the air columns and draw air in through the open end of theouter drum niitted into the inlet opening 30, of the rotor, a

I9 and direct the same transversely through the rotor between spaceddrums I6 and I9. Discharge vanes 22 connect the inner drum I6 with thelouter drum I9 at the outer end of the rotor, and these discharge vanesmay be integral with a ring 23, which ring is secured t9 the drum I6 asshown in Fig. l. The discharge vanes are curved backwardly as shown inFig. 4 in order to reduce the discharge speedlof the air leaving therotor through the discharge openingl 24 and thus reduce the consumptionof power. The edges of the vanes 22 are at a greater distance from thecenter of the rotorthan the edges of .the vanes'2l to insure enoughsuction and pressure to overcome the resistance of the air travelingtransversely through lthe rotor.

Extending around the periphery of the inner drum I6 between the intakevanes 2| and the discharge vanes 22 and substantially rllling the spacebetween the inner and outer drums is, a

circular filter element designated generally by the numeral 25. Thefiltering element is preferably formed of superimposed layers ofcorrugated board to form a plurality of elongated passageways 26 ofrelatively small -cross section extending transversely of the plane ofrotation of the rotor. Other material than corrugated board may ofcourse be employed for forming the passageways, but corrugated board isinexpensive and can therefore be readily replaced when necessary.

Referring to Fig. 5 showing a detailed view of the corrugated board lterconstruction, eachlayer may comprise a iibrous backing sheet -21 towhich a corrugated element 28 is adhesively secured. 'Ihe several layersmay be separated from each other by extra layers 29 of cloth or papermaterial to -strengthen the filtering element. f

In order to form a passageway for air to be ada peripheral housing 35for the rotor. A cover 36' for the other end of therotor may beconnected as at 31 to the peripheral housing portion 35. The end cover36 may be formed with an extension 38 through which filtered air may bedis--v charged. In order to control the discharge, a plurality ofAlouvers 39, which are pivoted as 'at 40, may be utilized. The louversmay have inner ex' tensions 4I which are pivotally connected to a commonbar 42, and yielding means 43 may be associated with the bar to normallymaintain the louvers in closed position. The yielding means is of suchstrength that the louvers will automatically open to the dotted lineposition of Fig. 1 in response to air pressure. The louver assembly ismounted on an end cover' 44 forthe extension 38. In order to provide forthe admission of inside air to mix with the outside air, a plurality ofopenings 45 may be formed inthe outer end of the housing portion 33.A-sleeve 46 which is provided with similar openings to the openings A45is rotatable between anges 41 to regulate theamount of air which may beadmitted through .f

inwardly -of the preliminary lter 48, and said heater orvcooler maycomprise a lowerv header 49.,

an upper header 56, and finned connecting tubes 5I. 4Taps 52 and 53maybe associated with the headers 49 and 50 respectively, and anadditional tap 54 is connected with a drain pan 55 for.

tates. A hollow passageway 51 leads to the motor chamber andcommunicates at 58 withv the rotor whereby some ofthe air'from the rotordischarge vanes is blown into 'the motor chamber to cool the motor.

In operation air drawn in from the exterior through the inlet conduit 3lmay be mixed with a predetermined amount of inside air admitted throughthe openings 45. The air then passes through the preliminary lter 48 andpast the pipes 5I where it is either heated or cooled, as desired. Thefiltering element 48 which is of ordinary structure will remove amajority of foreign matter from the air. It will, however, pass four toten per cent dust particles or the like, because these commercialfilters are not one hundred `per cent eflicient. The intake vanes 2|,

which are designed for impact free lpassing of the air, direct the airtransversely to the plane of ro'- tation of the rotor while the latteris rotating. While passing the vanes 2l, the air is accelerated up tothe maximum peripheral velocity, and the particles of dust and otherforeign matter are evenly distributed in the airjn the space 2i beforesaid particles enter the filtering element 25. It is preferred that thefiltering element have an inner portion 25" provided with lpassagewaysof larger cross sectional area than -the area of the passageways in themain portion of the lter. In addition the walls of the passageways arepreferably coated with an oil or vaseline-26'. The vanes 2| may also becoated with similar material to trap foreign matter thrown against saidvanes by acceleration forces, whereby the inertia. of said particles isutilized to cause said entrapment.

As the air travels through the passageways 26, the particles of dust andother foreign-matter in the air are subjected to the action ofcentrifugal.

force which causes the same to travel in a radially outward direction,whereby said dust par# ticles are thrown against the walls of thecorrugations and trapped by'the'coating thereon. The degree of aircleaning can be varied by varying the distance a, Fig. 5, by controllingthe-magnitude of the centrifugal force, and by controlling the timeperiod during vwhich said centrifugal force acts upon the air columns inthe fllter. As the air leaves the iiltering element, it is provers 39. v

The end member 44 carrying the louvers is removably held in position byset screws or'the like 59, and by loosening said set screws the endmember 44 may be rotated to bring the louvers into'd Referringv anydesired airdirecting position. now more particularly to Figs.'6 and "l,there is illustrated 'aform cfinvention which is particutremely neparticles l. rom air or gas. The rotor 60 of this form of the invention'comprises an inner drum 6I, and an outer drum- 62 formed of gether -asat 63 in such a manner as to provide a peripheral opening 64. The wallsof theouter pelled by the discharge vanes through 'the end.`

opening 24 of the rotor and out past the lou- 60 larly suitablefor remving smoke and other extwo complemental sections which are.bolted todrum$2 converge slightly toward said opening 64. The inner drum 8| ismounted on a shaft 65,-,and one end of said shaft is journaled in abearing 66 and extends outwardly beyond said bearing for connection witha source of power. The bearing 66 is supported by webbing B1 within aring 6,8 carriedl by the upper end of a standard 69. The ring 68 formsthe discharge opening 69 for the device.

The other end of the rotor shaft 65 is journaled in a bearing 1U, and said bearing is supported byspiders 1I within. a ring 12, the ring 12being mounted on the upper end of a standard 13.

Air admitted throughan inlet conduit 14 passes a preliminary iilteringelement 15 and then enters through the ring 12 around the bearing 10 tothe open end of the drum. Guide vanes 1d direct I said air, in a'mannerto be hereinafter described,

to the rotatable intake vanes 'VELv These vanes 11 are identical inconstruction to the vanes 2t of the form of invention shown in Fig. i.The air is then directed through a filtering element 18 havingpassageways of relatively large cross section and through a ilteringelement 19 having passageways of small .cross section. The filteringelements 18, 19 and 82 may be identical in construction to theAfiltering elements 25' and- 25 of the principal form of the invention.As the air passesthrough the ltering elements 153, F9 and 82, any oilmist in the air or any nicotine or other products from smoke aredeposited by centrifugal force on the walls of the corrugations formingthe passageways. This material then creeps along said walls and isthrown by centrifugal force toward the opening tit in the outer drum 62.The material released through the opening 56 will fall upon the innerwall of the outer housing and may be removed through a drain cock 8l.

The cleaned air is then discharged through the opening 69 by thedischarge vanes d3, which discharge vanes are similar in construction tothe discharge' vanes 22 of the principal form of the invention.

The guide vanes i6 have their inner edges secured to the periphery ofthe bearing 'lil as shown in Figs. 6 and 7, and the outer edges of thevaries are looped as at 8f3. Pins S5 extending through said loops havetheir outer ends angled and connected to a rotatable member 86. Themember may be rotated by manipulation of a lever 81 to ex the guidevanes to one of the dotted line positions shown in Fig. 7. Thus thevanes may be deflected either against or with the direction of rotationof the rotor to control the volume of air admitted to the rotor.

The rotor of this form of the invention is supported by two bearings sothat a higher rotor speed is permitted. In addition the rotor drums arerelatively long so that air columns are subjected to the action otcentrifugal force for a relatively long period of time'. Thus a highcleaning efficiency is obtained.

The filtering elements lt, le and are preferably of corrugated board sothat the latter may be discarded when they are filled with deposits. Anyother suitable material may,v however, be employed for forming theelongated passageways.

In cases where gas or air under high pressure is to be cleaned, theinlet and outlet openings of the lter maybe modified for convenientconnection to pipe lines o'r the like. The housing and rotor drums mustalso be formed with heavy enough walls to withstand the increasedpressures.

In cases where pressures are high, but in which it isdesired to keep thepressure low between the housing 80 and the outer drum 12 in order toreduce power consumption, then suitable stulng boxes must be employed-between the rotor and the stationary parts.

Figures 8, 9 and 10 illustrate a design which is particularly suitablefor industrial purpose, such as dust collecting, smoke cleaning, and theven= tilating of large buildings. It may be also employed to humidifyand cool air. 'I'he device includes 'a rotor 88 formedof two parts at,Qt. The rotor is mounted on a. shaft 92 driven by an electric motor 93,and the drive shaft may be journaled in bearings 94. Spaced from therotor 88 is an outer rotor portion formed of two parts and 96, whichparts are rotatable with the inner rotor parts 89 andA 9B respectively.A lower housing portion 91 surroundsthe lower rotor parts and forms adust or liquid collecting receptacle.

An upper housing' part 98 is spaced from and connected to an inner airdirecting member di, and the housing 9s has its upper end formed with adischarge opening @9.

,The air or gas to be cleaned flows into the duct it@ and is drawn in bythe rotor and is acted on by thevanes mi which function in a mannersimilar to the vanes 2t of the form ot' invention shown in Fig. 1. Theair then passes through the plurality of elongated compartments itt ofthe iiltering element HB3. This filtering element is preferably formedof metal and in cross section has the appearance shown in Fig. 9.

it is preferred to keep the distance between the these walls until theyreach the outer chamber l.

The foreign matter is also thrown by acceleration force against thecross partitions Mit' whereby the inertia of said particles is used tocollect the same. The rotor portions d@ and dei are adjustable toprovide an annular opening at m5, and said adjustable position isindicated by dotted lines in Fig. 8. This adjustment is permitted bymovement of the member ldd along the key-way it?, which movement may bebrought about by rotating a shaft Hit to operate a clutch fork M9. Withthe lower and upper rotor portions separated tol a desired degree, asindicated by dotted lines at ltd, the foreign matter will be thrown bycentrifugal force exteriorly of the rotor and' into the receptacle 9i.The air may then pass through another ltering element @tid and bedischarged through the discharge opening de. v A suspended hammer it?)maybe utilized to impart vibrations to the rotor to facilitate movementof the fine particle# along the walls of the filtering elements and toprevent 'clogging of the small passageways of the iilters. Thesevibrations may also. be imparted by an electromagnet i i@y which isincited by electrical impulses to impart vibrations of high lfrequencyto metal of the rotor and to the small air columns moving through thefiltering elements to augment the movement or" foreign matter in saidair.

One or more nozzles lli may be utilized to spray a stream of liquid,such as water, onto the surface of the filters to help imprison theparticles and to keep the compartments clean by the continued rinsingaction of the spray. Where a`spray'is employed, the anges at the openingE05 of the outer rotor portion are provided with backwardly curved ribsI I3 so as to always maintain spaces H4 through which the liquid may bedischarged to the collecting receptacle 91 (see Fig. 10).

'I'he deposits in the collecting receptacle 91 will settle at the bottomthereof and may be removed through the drain opening H5. Liquid to thenozzles H2 may be supplied through an inlet line H6. f v

The cleaned air or 'gas is discharged through the opening 99 and into asuitable outlet duct connected to the iiange Ill surrounding the opening99. This discharge is augmented by backwardly curved discharge vanesIUI' which function in the same manner as the discharge vanes 2'2 of theprincipal form of thepinventlon.

The spray of liquid discharged by the nozzle H2 may perform a coolingand dehumidifying function if cold water is utilized, or a heating andhumidifying function ifhot water is Vemployed.

It is apparent that in all forms f the invention the air to be cleanedis subjected to the action of centrifugal force and to the action ofinertia such as acceleration and deceleration while traveling through aplurality of elongated passageways of restricted radial width, theforeign matter in` the air being either trapped on the walls of thefilter by a sticky coating, 0r said foreign matter and moisture beingdirected by the centrifugal force through release openings of the rotorinto a collecting receptacle.

The construction is highly efficient and can be employed for any of thepurposes mentioned and for a variety of other purposes. In addition itmay embody heating or cooling features as described.

In the claims where the term "air is employed, it must be understoodthat this contemplates any other gas.

Although only a few forms of the invention have been shown anddescribed, it Vis obvious that various changes and modications maybe'made without departing from the spirit of the invention, and all ofsuch changes are contemplated as may come within the scope of theclaims.

What I claim is: Y

1. An air lter comprising a rotor, a plurality of superimposed annularlayers of corrugated board mounted on said rotor and rotatable therewithto form passageways of relatively small radial width, and means formoving air Vto be cleaned through said passageways, said air beingsubjected to the action of centrifugal force whereby particles offoreign matter in the Yair are deposited by centrifugal force on lthewalls of said passageways.

2. An air lter comprising a rotor, means rotatable with said rotorforming a plurality lof narrow elongated passageways, and means formoving air to be cleaned through said passageways, said air beingsubjected tothe action of centrifugal force whereby particles of foreignmatter in the air are deposited by centrifugal force Bn the walls ofsaid passageways, and there being v passageways communicating with saidrst passageways and with the outlet end of the rotor which are of lesscross sectional area than to be cleaned from one end of the rotor to theother through sai'd ''lter space, said space beingq formed with amultitude of elongated passageways of small cross-section whichsubstantially fill said space in honeycomb fashion and all of whichextend transverselyY of the plane 'of rotation of the rotor, the radialdimension of said deposited by centrifugal force on the walls of eachpassageway.

4. An air filter comprising a rotor having an annular filter space, andnieans for moving air to be'cleaned from one end-of the rotor to theother through said filter space, said spac'e'heingY filled with aplurality of radially spaced annular partitions .and the lannular spaceof each adjacent pair of partitions beingidivided to form a multitude ofelongated passageways of small cross-section which extend transverselyof the plane of rotation of the rotor, each of said passageways servingto individually confine a co1- umn of air of small cross-section and tocause each of said columns to move in a straight line from one end ofthe filter space to the other, said air being subjected to the action ofcentrifugal force whereby particles of foreign matter in the air aredepositedY by centrifugal force on the walls of each passageway. Y.

5; An air lter comprising a rotor having an annular filter space, andmeans for moving air to be cleaned from one end of the rotor to theother through said filter space, said space'being iilled with aremovable ltering element includ- 'ing a` plurality of radially spacedannular partitions and the annular space of each adjacent pair ofpartitions being divided to forma multitude of elongated passageways vofsmall crosssection which extend transversely of the plane of rotation ofthe rotor, each of said passageways serving to individually confinearcolurn'n of air of small cross-section and to cause each of saidcolumns to move in a substantially straight I other through said lterspace, said space being I filled' with superimposed -layerslof-corrugated board to form a multitude of elongated passageways ofVsmall cross-section which extend transversely of the plane of rotationof the rotor. each of said passageways serving-to individually conne acolumn of :of small crow-section and to cause eachfof said columns tomove in a substantially straight line from one end of the filter spaceto thel other, said being subjected. to the action of centrifugal forcewhereby particles of foreign matterA inthe air are deposited centrifugalforce omthe walls of each' :wr-

CARL A.

